One place I worked in the 90s had a bunch of meetings/tutorials to try to sell all the C programmers on Object Oriented Programming in general and C++ in particular -- the software in question was super complicated and massive and IMHO could have benefitted from some judicious application of OOP concepts like separation of concerns -- but it got caught in a rut of just constantly trying to explain OOP to middle aged programmers who had only ever written and thought in imperitive code.